实现购物车点击添加的抛物线动画效果

public class MainActivity extends Activity {

private ImageView top;
private ImageView bottom;
private ImageView animImageView;
private ViewGroup anim_mask_layout;// 动画层

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
top = (ImageView) findViewById(R.id.top);
bottom = (ImageView) findViewById(R.id.bottom);

}

//点击添加按钮开始动画
public void startAnim(View view) {
// 记录开始的位置
// 一个整型数组，用来存储按钮的在屏幕的X、Y坐标
int[] startLocation = new int[2];
// 这是获取购买按钮的在屏幕的X、Y坐标（这也是动画开始的坐标）
top.getLocationInWindow(startLocation);

// 创建要做动画的ImageView
animImageView = new ImageView(this);

// 设置animImageView的背景
Drawable background = top.getBackground();
//得到指定缩放大小的图片
Drawable zoomDrawable = zoomDrawable(background, dip2Px(this, 200), dip2Px(this, 200));
animImageView.setBackgroundDrawable(zoomDrawable);

// 开始执行动画
setAnim(animImageView, startLocation, top);
}

/**
* 设置动画
*
* @param v             要做动画效果的图片
* @param startLocation 点击的X,Y轴位置
* @param view          被点击的图片
*/
private void setAnim(final View v, int[] startLocation, final View view) {

anim_mask_layout = null;
anim_mask_layout = createAnimLayout();
anim_mask_layout.addView(v);// 把动画小球添加到动画层
final View viewa = addViewToAnimLayout(anim_mask_layout, v, startLocation);
int[] endLocation = new int[2];// 存储动画结束位置的X、Y坐标
bottom.getLocationInWindow(endLocation);// shopCart是那个购物车

// 计算位移
int endX = endLocation[0] - startLocation[0];// 动画位移的X坐标
int endY = endLocation[1] - startLocation[1];// 动画位移的y坐标

//如何实现抛物线效果？
//在X轴上保持匀速，在Y轴上加速就实现抛物线运动
/*
* AccelerateDecelerateInterpolator 在动画开始与结束的地方速率改变比较慢，在中间的时候加速
AccelerateInterpolator  在动画开始的地方速率改变比较慢，然后开始加速
AnticipateInterpolator 开始的时候向后然后向前甩
AnticipateOvershootInterpolator 开始的时候向后然后向前甩一定值后返回最后的值
BounceInterpolator  动画结束的时候弹起
CycleInterpolator 动画循环播放特定的次数，速率改变沿着正弦曲线
DecelerateInterpolator 在动画开始的地方快然后慢
LinearInterpolator   以常量速率改变
OvershootInterpolator    向前甩一定值后再回到原来位置
* */

TranslateAnimation translateAnimationX = new TranslateAnimation(0, endX, 0, 0);
translateAnimationX.setInterpolator(new LinearInterpolator());
translateAnimationX.setRepeatCount(0);// 动画重复执行的次数
translateAnimationX.setFillAfter(true);

TranslateAnimation translateAnimationY = new TranslateAnimation(0, 0, 0, endY);
translateAnimationY.setInterpolator(new AccelerateInterpolator());
translateAnimationY.setRepeatCount(0);// 动画重复执行的次数
translateAnimationX.setFillAfter(true);

ScaleAnimation scaleAnimation = new ScaleAnimation(1, 0.2f, 1, 0.2f);
scaleAnimation.setInterpolator(new AccelerateInterpolator());
scaleAnimation.setRepeatCount(0);// 动画重复执行的次数
scaleAnimation.setFillAfter(true);

AnimationSet set = new AnimationSet(false);
set.setFillAfter(false);
set.addAnimation(scaleAnimation);
set.addAnimation(translateAnimationY);
set.addAnimation(translateAnimationX);
set.setDuration(600);// 动画的执行时间
viewa.startAnimation(set);
// 动画监听事件
set.setAnimationListener(new Animation.AnimationListener() {
// 动画的开始
@Override
public void onAnimationStart(Animation animation) {
v.setVisibility(View.VISIBLE);
}

@Override
public void onAnimationRepeat(Animation animation) {
}

// 动画的结束
@Override
public void onAnimationEnd(Animation animation) {
v.setVisibility(View.GONE);
}
});

}

/**
* @param
* @return void
* @throws
* @Description: 创建动画层
*/
private ViewGroup createAnimLayout() {
ViewGroup rootView = (ViewGroup) ((Activity) this).getWindow().getDecorView();
LinearLayout animLayout = new LinearLayout(this);
LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.MATCH_PARENT);
animLayout.setLayoutParams(lp);
animLayout.setBackgroundResource(android.R.color.transparent);
rootView.addView(animLayout);
return animLayout;
}

private View addViewToAnimLayout(final ViewGroup parent, final View view, int[] location) {
int x = location[0];
int y = location[1];
LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT,
LinearLayout.LayoutParams.WRAP_CONTENT);
lp.leftMargin = x;
lp.topMargin = y;
view.setLayoutParams(lp);
return view;
}

/**
* 将drawable对象进行指定大小的缩放
*
* @param drawable 原图
* @param w        图片缩放后的宽
* @param h        图片缩放后的高
* @return
*/
public Drawable zoomDrawable(Drawable drawable, int w, int h) {
int width = drawable.getIntrinsicWidth();
int height = drawable.getIntrinsicHeight();
Bitmap oldbmp = drawableToBitmap(drawable); // drawable 转换成 bitmap
Matrix matrix = new Matrix(); // 创建操作图片用的 Matrix 对象
float scaleWidth = ((float) w / width); // 计算缩放比例
float scaleHeight = ((float) h / height);
matrix.postScale(scaleWidth, scaleHeight); // 设置缩放比例
// 建立新的 bitmap ，其内容是对原 bitmap 的缩放后的图
Bitmap newbmp = Bitmap.createBitmap(oldbmp, 0, 0, width, height, matrix, true);
return new BitmapDrawable(newbmp); // 把 bitmap 转换成 drawable 并返回
}

/**
* 将drawable 转换成 bitmap
*
* @param drawable
* @return
*/
public Bitmap drawableToBitmap(Drawable drawable) {
int width = drawable.getIntrinsicWidth(); // 取 drawable 的长宽
int height = drawable.getIntrinsicHeight();
Bitmap.Config config = drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888
: Bitmap.Config.RGB_565; // 取 drawable 的颜色格式
Bitmap bitmap = Bitmap.createBitmap(width, height, config); // 建立对应
// bitmap
Canvas canvas = new Canvas(bitmap); // 建立对应 bitmap 的画布
drawable.setBounds(0, 0, width, height);
drawable.draw(canvas); // 把 drawable 内容画到画布中
return bitmap;
}

// dp转换为像素px
public static int dip2Px(Context context, float dp) {
final float scale = context.getResources().getDisplayMetrics().density;
return (int) (dp * scale + 0.5f);
}

}